If you can’t build it, copy it. Scientists have had a hard time reconstructing the photonic crystals that make butterfly wings shimmer with light (01/29/2003), so they made, in effect, a carbon copy. PhysOrg described how scientists at Penn State made impressions of the regularly-spaced geometric shapes from a butterfly wing and transferred it to glass, leaving a “positive mold that looks the same as the butterfly wing from the top.” Maybe instead of biomimetics this could be dubbed biomimeographics. What do they want to do with their replicated photonic crystal? They have their eyes on semiconductor devices, infrared sensors, solar energy concentrators and other things no one has thought of yet. What they know is that the “structural color” reflected by these crystals will be pure and intense. That’s bound to be useful or just pretty.True science seeks to understand a natural phenomenon with observation, equations and experiments, with an eye toward improving human life. It’s not necessary to tell a story about how the butterfly invented a technology that human intelligence can photocopy but not yet engineer.(Visited 10 times, 1 visits today)FacebookTwitterPinterestSave分享0
Share Facebook Twitter Google + LinkedIn Pinterest Soon it will be time to heat the greenhouse. The heating system may have been working when it was last used this past spring, but those systems have had several warm and humid summer months to degrade.A heater or boiler out of tune will use more fuel than necessary and could produce harmful exhaust inside the greenhouse. In addition, new cracks or other air gaps in the structure will quickly leak heat. Checking over the greenhouse structure and heating systems as fall approaches will save your heating costs.HeatersService space heaters or boiler serviced once a year. Check with your natural gas or propane provider to see if heater inspection is a service offered. Hire a qualified service technician to perform regular maintenance. Gains in efficiency can more than pay for a professional tune-up.There is some basic maintenance for a gas space heater, but only perform as much self-service as you feel comfortable with. Before the heating season check heaters, air inlets, and chimneys for bird nests and other debris. Clean gas burners with a bristle brush and compressed air. Inspect the heat exchanger and exhaust pipe for cracks. A cracked heat exchanger or vent pipe will allow harmful gasses such as carbon monoxide and ethylene into the greenhouse. Electrical connections should be tight. If fuel oil is used, replace the fuel filter. Check pilot or spark ignition for proper operation.Turn on gas burners and inspect gas flames. The burner flame should be blue. A yellow flame indicates incomplete combustion and could be caused by a dirty or misaligned orifice. An unstable flame may be an indication of drafts from a cracked heat exchanger or other air leaks. Check gas supply lines for leaks with a soap solution while the gas is on. Make sure propane tanks have adequate pressure or that fuel oil tank is full.Regular heating system maintenance results in a 2% increase in efficiency. For a 30-foot by 100-foot greenhouse 2% can save: 285 therms of natural gas, 330 gallons of propane, or 200 gallons of fuel oil. The savings should more than pay for the service. Seal air leaksExpandable foam, weather stripping, and caulking can be used to seal air leaks in the greenhouse structure where heat can escape. Check for air gaps around doors, ventilation fans, and other equipment mounted through the glazing. Plastic film can become cut, punctured, or torn with regular use throughout the year. It is very easy to accidently poke a long handled tool through polyethylene film. Inspect the film and use an appropriate tape to seal any holes.Keep photosynthesis in mind when sealing the greenhouse. Plants require carbon dioxide for photosynthesis. If the greenhouse is too well sealed, carbon dioxide levels will drop and photosynthesis will decrease. Monitoring carbon dioxide levels in the greenhouse will help to determine if there is enough ventilation for plants to grow. An air exchange rate of 0.1 to 0.3 exchanges per hour is necessary to ensure sufficient carbon dioxide. An alternative option to ventilation is the installation of a carbon dioxide burner.In addition to using up carbon dioxide, plants in an air-tight greenhouse will raise relative humidity. It is therefore necessary to actively remove moisture from a well-sealed greenhouse. To maintain acceptable humidity levels, a greenhouse will require between 0.3 and 1 air exchanges per hour. The exact air exchange rate required is dependent on outside humidity level. Measuring relative humidity in the greenhouse will be necessary to ensure proper humidity levels for plant transpiration and disease control.Louvers are designed to seal when ventilation fans are not operating. If ventilation fans will be needed for dehumidification during the winter, lubricate louvers so they can easily shut when fans are turned off. If fans will not be used during the winter, consider sealing them with plastic or Styrofoam insulation inside and out. Any other openings in the greenhouse structure that will not be used during winter such as cooling pads should be well sealed.Light LevelLimited light in the winter due to low solar angle and short daytime can be made worse by dirty glazing. Glazing should be cleaned prior to the winter season. Double layer plastic film should be inflated with outside air for higher light transmission. If high humidity greenhouse air is used to inflate double layer plastic covering, condensation will form between the layers and reduce light transmission. Inflation to the proper static pressure is important for maximizing the insulating properties of the glazing. Double layer plastic film greenhouses naturally have lower light transmission than single layer films, so make sure you are taking full advantage of the heat savings by keeping the film properly inflated. Also in preparation for the low light levels associated with the winter, check the operation of supplemental lighting. Prevent freezingAny water lines that may be subjected to freezing temperatures should be blown out or otherwise winterized. Make sure equipment, such as pressure washers, are winterized so freezing water does not cause damage. Cooling systems for internal combustion motors must have antifreeze in the coolant. Dr. Peter Ling is an Associate Professor and Extension Specialist in the area of controlled environment plant production. He can be reached at 330-263-3857 or [email protected] This column is provided by the OSU Department of Food, Agricultural and Biological Engineering, OSU Extension, Ohio Agricultural Research and development Center, and the College of Food, Agricultural, and Environmental Sciences. Luke Power is a Research Associate with Dr. Ling.
GIFs have been given new life with the popularity of the cinemagraph. Here are two quick ways to create cinemagraphs, either in Photoshop or Final Cut Pro X.Don’t get left behind. Cinemagraphs are a hot new visual tool and they’re perfect for catching the attention of your target audience. Here’s everything you need to know to create a cinemagraph in Final Cut Pro X and Photoshop.What Is a Cinemagraph?Wikipedia defines a cinemagraph as a “still photograph in which a minor and repeated movement occurs.”Cinemagraphs are essentially GIFs that are frozen, but with one area of the image showcasing movement. These “moving photographs” make images dynamic and add visual interest and a creative touch.Take a look at this example from Jamie Beck and Kevin Burg, the NYC-based visual artists who helped popularize this photographic technique.Image from Cinemagraphs.com.How to Make a CinemagraphSo at this point you’re surely wondering — how do I create my own cinemagraph?Cinemagraphs are created from a short snippet of video or a series of consecutive still images. By masking the part of the image you want frozen, you can reveal the area in the image where you’d like the motion to occur.You can create a cinemagraph using the Animation tools in Photoshop. This blog post by Spoon Graphics walks you through the steps of creating a cinemagraph effect in PS.If you’re more comfortable in a video editing application, the following video tutorial by Peter Wiggins from FCP.co will show you how to create a cinemagraph in Final Cut Pro and Motion.If you’d like to learn more about working in FCPX, spend a few minutes exploring the Final Cut Pro X section of the PremiumBeat blog. We’ve compiled plenty of tips, tricks, and techniques with your workflow in mind.Have any of your own cinemagraphs that you’d like to share? Do so in the comments below!
Creating depth is more than just a shallow depth of field. Take a look at some of the best ways you can use depth to your advantage.Cover image via Shutterstock.While many factors can make your work look more cinematic, depth is a key component. While a shallow depth of field is a great beginning, there are many things you can do as a cinematographer to help depth play a key role in your work.Depth of FieldImage via Shutterstock.I’ll get the easy one out of the way first. A shallow depth of field, for example a low T-stop, will quickly give you the best perception of depth without any additional lighting. Using this method is the first stop on the way to creating depth in your images.Foreground and BackgroundImage via Shutterstock.Use multiple layers of depth. This can help a scene really pop by creating distance between your foreground, background, and subject. Most cinematographers rely simply on the blur of the background to create depth. However, by introducing depth to the foreground, you can make your scene feel more immersive. For example, if your talent is having a conversation at the dinner table, frame the shot so you see their glass of water out of focus in the foreground.BokehImage via Shutterstock.Yes, bokeh creates depth. However, how often do you think of creating and curating your own bokeh? It’s quick and easy and adds loads of production value. If you’re shooting a dialogue scene in a city at night, you can really make it come alive by taking some low wattage fresnels and sticking them 100 feet down the strip. You can take it up a notch and gel those lights in a variety of colors.If you’re filming an interior scene, introduce practical light sources in the background. They can be something as simple as some Christmas lights strung around a window frame.HighlightsImage via Shutterstock.Have you ever been in a super dull location and wondered how you were going to make it look decent? One of my favorite ways to improve any mundane location is to introduce subtle splashes of highlights on the walls. These varying light ratios introduce a perception of depth you wouldn’t get otherwise. A great example of this is the show Atlanta. In the second episode, Earn finds himself at the police station. As a location, it’s fairly mundane. However, the cinematographer plays with highlights on the walls to really give the imagery life.Use a hard source light like a fresnel and shoot it directly onto the back wall. Then use a solid flag and cut down the spill to make it a hard cut. Introducing this highlight onto a wall can really elevate the perception of depth.As a cinematographer, there are many tools and methods at your disposal to make your images more cinematic. By understand depth as more than just “shallow depth of field,” you can really elevate your work.Looking for more cinematography tips? Check out these articles.Cinematography Tip: Use Fog To Add Depth to Your ShotThe Pros and Cons of a Shallow Depth of FieldSimulating Depth Using Vanishing Points in After EffectsHow Symbolic Framing Adds Depth to Your ShotAdd Depth with the Parallax Effect in After Effects